| 摘要 |
PROBLEM TO BE SOLVED: To downsize a battery through improvement of volume efficiency of a winding type flat electrode group.SOLUTION: A positive electrode plate 122 and a negative electrode plate 124 are wound around with a fine porous separator 121 made of polyethylene, and are compressed to manufacture a wound electrode group 120. In the flat wound electrode group 120, a flat space 120S is formed in a winding center, and a flat member 120F flatten out in a plate shape is arranged at an end part in a gap. The flat member 120F is originally a cylindrical-formed wound auxiliary member 120C, but then, it is flattened together with the flat space upon compressing of a basic forming 120P of the wound electrode group. By compressing and flattening out the basic forming 120P of the wound electrode group made by laminating the positive electrode plate 122, the negative electrode plate 124 and the separator 121 in a thickness direction and winding it, its volume is greatly reduced to finally obtain the wound electrode group 120 with high volume efficiency. |
